Ferns and Fern Allies of Wisconsin
digitatum (Dillenius ex E. Braun) Holub
(= Lycopodium digitatum Dillenius ex A. Braun
This species and D. complanatum have conspicuously broad, flattened
branches (2.8-3.9 mm wide) that are very distinctive and unlikely to be
confused with the other species of this family. The leaves are scale-like
and mostly appressed to the stem, and the leaves on the underside of the
branch are conspicuously smaller than those of the upper or lateral surfaces.
The upper surface of the leaves is green and shiny, and the underside
is paler green. The branches lack the annual constrictions of D.
complanatum. Spores are borne in strobili on conspicuous peduncles,
and the tips of the strobili are often
sterile, unlike the completely fertile strobili of D. complanatum
(as in most circumstances it is a good idea to look several plants to
determine the tendencies of the population).
Diphasiastrum digitatum ranges throughout the northeastern U.S.A., south to northern Georgia and Alabama and west to the eastern portions of Missouri, Iowa and Minnesota. In Wisconsin it is found nearly statewide except for the southeastern counties. Habitats include a variety of forests and forest openings.